II. MIDAS, Geoffr. 138 1. rosalia (Linn.) 138 2. geoffroyi (Pucher.) 139 3. oedipus (Linn.) 140 4. labiatus, Geoffr. 141 5. rufiventer, Gray 142 [alpha]. mystax, Spix 142 [beta]. pileatus, Is. Geoffr. 143 6. weddelli, Deville 143 7. nigrifrons, Geoffr. 143 8. fuscicollis, Spix 144 9. chrysopygus (Wagner) 144 10. nigricollis, Spix 145 11. illigeri (Pucher.) 145 12. bicolor, Spix 147 13. midas (Linn.) 148 14. ursulus, Geoffr. 148 FAMILY II. CEBIDÆ 150 SUB-FAMILY I. NYCTIPITHECINÆ 152 I. CHRYSOTHRIX, Kaup 152 1. usta (Is. Geoffr.) 154 2. entomophaga (d'Orb.) 155 3. sciurea (Linn.) 156 4. oerstedi, Reinh. 158 II. CALLITHRIX, Geoffr. 158 1. torquata (Hoffm.) 159 2. cuprea, Spix 160 3. amicta (Humb.) 161 4. cinerascens, Spix 161 5. moloch (Hoffm.) 162 6. ornata, Gray 162 7. personata, Geoffr. 163 8. nigrifrons, Spix 164 9. castaneiventris, Gray 164 10. melanochir, Neuwied 165 11. gigot, Spix 165 III. NYCTIPITHECUS, Spix 166 1. trivirgatus (Humb.) 168 2. lemurinus, Is. Geoffr. 168 3. rufipes, Sclater 169 4. azaræ (Humb.) 170 5. felinus, Spix 170 SUB-FAMILY II. PITHECIINÆ 173 I. BRACHYURUS, Spix 174 1. melanocephalus (Humb.) 175 2. rubicundus, Is. Geoffr. 176 3. calvus, Is. Geoffr. 177